1. Field of the Invention
The present invention relates to a solid golf ball providing excellent hit feeling, exhibiting a large carry, remarkably spinning when hit from the rough or on a rainy day, and easy to stop.
2. Description of the Prior Art
In general, a golf ball prepared by forming a rubber thread layer on a liquid core and covering the same with balata is excellent in hit feeling and controllability, and widely used by experienced golfers and pro golfers. However, the golf ball having such a structure requires complicated manufacturing steps and is inferior in cutting resistance, and hence various types of soft cover materials are recently proposed in place of the balata cover.
For example, soft ionomer resin is employed as the base resin for such a cover for a golf ball, as described in U.S. Pat. No. 4,884,814 (1989). However, a golf ball covered with such soft ionomer resin exhibits an inferior spinning quantity under a wet condition as compared with that under a dry condition, and is hence insufficient in spinning retention.
GB2311530 (1997) proposes a golf ball covered with base resin mainly composed of a hot two-component mixture of ionomer resin and a styrene-butadiene-styrene block copolymer having a polybutadiene block containing epoxy groups or a styrene-isoprene-styrene block copolymer having a polyisoprene block containing epoxy groups. The composition forming the cover has flexural rigidity of 50 to 300 MPa and Shore D hardness of 40 to 60. While the golf ball provides excellent hit feeling and controllability and can satisfy flyability and cutting resistance, this technique does not aim at improving spinning retention.
The inventors have already proposed a technique of improving hit feeling of a golf ball and increasing the spinning quantity of the golf ball hit with a short iron by employing a solid rubber core containing oily matter and a soft cover material (U.S. Pat. No. 5,716,293 (1998)).
However, this golf ball, employing oilproof rubber and hard ionomer resin on the outer side of the solid rubber core, must still be improved in bounce and hit feeling.
An object of the present invention is to provide a soft solid golf ball providing excellent hit feeling as well as a large carry, exhibiting a large spinning quantity also when hit from the rough or on a rainy day, and easy to stop.
The present invention provides a solid golf ball consisting of a core and a cover coating the core, characterized in that the cover is made of a mixture of ionomer resin, thermoplastic elastomer and a tackifier and has Shore D hardness of at least 40 and not more than 65.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention.